1. Field of the Invention
The technology relates to the field of cosmetic chemistry, and more particularly to formulations that are useful, for example, in the removal of “dead” skin cells from the epidermis, commonly known as exfoliant or microdermabrasion formulations and that may also have other functions, such as moisturizing the skin.
2. Description of the Related Art
According to a report at www.info.ibtpartners.com, the field of cosmetics is a growth sector globally. The article which was published on May 20, 2013, states: “The global cosmetics industry is estimated to be worth $495 billion in 2012. Growth has clearly come from expanding geographic markets: India is reckoned to be growing at +15% per annum while the Chinese market could overtake Japan within 5 years. But growth is also coming from newly defined sectors: anti-aging, men's care, sun care, organic cosmetics and the so-called “cosmeceuticals” to name the most obvious. These sectors appeal to a growing audience, including Baby-boomers, Gen X-ers, and increasingly, Gen Y-ers.
Several of the niche-markets identified in the above report, and perhaps especially the well-heeled “Baby-boomers,” have shown a desire to improve the appearance and condition of their skin through the use of anti-wrinkle or “anti-aging” formulations, moisturizers, exfoliants, and more recently, microdermabrasion treatments, as a sub-category of exfoliant treatment. In general, any treatment that removes the outer layer of dead skin cells to expose “new skin” beneath may be classified as a exfoliant treatment. Usually, the exfoliation is carried out through either chemical or mechanical means, or a combination of both. In the chemical exfoliant formulations, the more typically used active chemical agent may be an acid, such as salicylic acid, glycolic acid, citric acid, or malic acid. The alpha and beta hydroxy acids are also known to be useful in exfoliation. Fruit enzymes may also be used as the active chemical agent. In its mechanical aspect, exfoliation usually involves the use of an abrasive which includes particulates of a particular size and type. Examples of such mechanical exfoliant formulations use the abrasive properties of particulates such as salt crystals, pumice, volcanic rock, crushed apricot kernels or almond shells, crystalline sugar, oats, and natural or synthetic micro-beads. In other mechanical treatments abrasive materials may also be used, such as loofah sponges, brushes, microfiber cloth, crepe paper, and the like that have a texture that promotes mechanical removal of dead skin cells during scrubbing.
Microdermabrasion has in the past typically been a mechanical abrasion technique used by professionals in med spas, physician's offices, and in salons to remove the outermost layer of dead skin cells from the epidermis, while using a suction machine to lift up the skin during exfoliation. More recently, the term microdermabrasion has also been applied to over the counter formulations that include fine particulates that are capable of performing a mechanical exfoliation.
There are several examples of particulate-containing formulations in the patent literature. For example, U.S. Pat. No. 7,025,976 uses a crystalline emulsion that includes coated crystals in a carrier to carry out microdermabrasion. U.S. Pat. No. 7,482,314 has a microdermabrasion composition that includes surfactant (20-60%), volatile silicone oil (5-60%), an anhydrous solvent, and 1-25% of a (water-soluble) salt. The water-soluble salt is not dissolved, but is present at a particle size of 50 to 2000 microns and acts as an abrasive. U.S. Pat. No. 8,084,409 is directed to a microdermabrasion soap that has about 15% of an abrasive compound, such as magnesium oxide, in a particle size of 120 to 200 microns. US Patent Application Publication 2002/0086039 is directed to microdermabrasion formulations that include bio-glass, or hydroxyapatite. The bio-active glass and hydroxyapatite are in particulate form. US Patent Application Publication 2003/0049291 is directed to a cream that contains abrasive particles, and the cream is asserted as useful in microdermabrasion. US Patent Application Publication 2005/0169868 is directed to an exfoliating composition that includes at least three insoluble particulate ingredients that are abrasive.
A concern in the use of microdermabrasion formulations and devices, regardless of source, is the potential for skin irritation and discomfort from applied chemicals, such as acids and enzymes. Some abrasive particles may also raise concerns regarding skin irritation or discomfort. Further, harsh abrasion may also damage underlying “new skin” during removal of the upper dead skin cells, especially if not carefully controlled by an experienced skin-care professional. Moreover, once new skin is exposed, the new skin may rapidly “dry out” and become damaged. To avoid such drying out and damage, microdermabrasion treatment may be immediately followed by the application of formulations that are intended to moisturize, soothe and/or reduce the potential for the newly-exposed skin to rapidly lose moisture.